CA2055705A1

CA2055705A1 - Disposable cartridge for sampling and analyzing body fluids

Info

Publication number: CA2055705A1
Application number: CA002055705A
Authority: CA
Inventors: James H. Macemon; Mark S. Schlosser
Original assignee: Individual
Current assignee: Spacelabs Medical Inc
Priority date: 1990-11-16
Filing date: 1991-11-15
Publication date: 1992-05-17
Also published as: EP0486059B1; DE69124075D1; US5143084A; DE69124075T2; EP0486059A1

Abstract

DISPOSABLE CARTRIDGE FOR SAMPLING
AND ANALYZING BODY FLUIDS

Abstract of the Disclosure A disposable sampling cartridge for use with a blood sample analyzer. The cartridge includes a blood reservoir communicating with a hypodermic needle, a waste collection chamber adapted to receive waste fluids from the blood sample analyzer, and a plurality of ampules each containing a respective analyzing fluid adapted for use by the blood sample analyzer. Each of the ampules contain a piston, and the analyzing fluids in the ampules are expelled by forcing an actuating rod through a frangible wall of the ampule to displace the piston. In one embodiment, the analyzing fluids are withdrawn through a conduit in the actuating rod while the blood and spent analyzing fluids flow through the blood reservoir port on which the hypodermic needle is mounted.. In another embodiment the waste fluid flows through an inlet port while the analyzing fluids from the ampules flow through a common port outlet port which selectively communicates with the blood reservoir and the ampules by a valve arrangement.

Description

2~7~5 D~iQ9 D~POSABLE CARTPclDGr~ FOR SAMPLING
~L~L~IIIDS

Te~hnical Field This i~vention relates to a device for collecti lg blood from 15 blood vessels, ~or allowing the blood to be inexpensively a~d quicldy analyzed, and for safely and easily collecting and disposing of waste blood and other ~uids resulting from the analysis.

Back~r~d of th~I~ve~io~
Conve~ional blood an~lyzing systems include a syringe into which the blood is collected, and an analyzer which analyzes the blood for such parameters as chemical composi~ion, blood gas constituents, pH, etc.
Two ~rpes of synnges have been used to talce blood samples. I~e firs~ type, which is used to sample~ affenal blood, includes a vented piston 25 arrangement~wherein a needle is inserted i~l a patient's arte~v, and the blood is forced into the syringe by the pressure diflerential betwee~l the absolut~ pressure in the arte~y and atrnospheric pressure. In this first ~ype, the air in the syringe is vented to the atmosphere as the sylinge fills with blood since the vented pislon allows air, but not blood, to pass. The second 30 ~pe oE syringe: includes a piston which is withdr~wn to increase the volume i n the syringe and thereby create a :vacuum to suction ~he blood from the patient. This second ~type of :syringe can be used to withdraw ~lood from a patient's :artery or vein.
Venous blood samples are also commonly taken using a 35 "VACUrAlNER." A "~CUTA NER" is a device consistin~ of two components, namely an adapter haY~ng a double-ended needle and an ..

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evacuated tes~ tube sealed with a resilient cap. The "VACUTAINER" is used by ~Irst inserting one end of the needle into a patient's blood vessel (usually a vein3 and then puncturing the test tub's resilient cap with the other end of the needle. The vacuum in the test tube then draws blood S through the needle and into the test tube. After suf~lciene blood has been drawn into the test hlbe, the needle is removed from the patient's blood vessel, and the test tube is separated from the adapter. The resiliency of the cap seals the puncture through the cap to prevent blood from leaking from the test tube and air from being drawn into the test tube.
Once the blood has been withdrawn from the patient into a syringe or test tube, the syringe or test tube is delivered to a lab for analysis.
The sample blood is then introduced into a conventional blood analyzer.
Conventional blood analyzers include a plurality of containers for respective calibrating or analyzing fluids, and a waste container ~or storing 15 the waste fluids and blood. Additionally, special pre-analyzed control fluids must be analyzed frequently to veriiy analyzer calibration and proper operation.
One problem with conventional blood analy7ers is that they are too large and expensive to be located at a patient's bedside.
20 ~ccordingly, the blood sample must be sent to a central lab fur analysis thereby requiring a relatively long period of time to obtain results. Under some circumstances, this delay can pose a serious threat to the health and safety of a patient since it may be necessary to delay correc~ive drug treatment or their procedures until the test results have been received.
25 Additionally, conventional analyzers are relatively complex to operate, making bedside use impra~ical. For instance, the technician must insure that the analyzing fluids are not depleted.
The need to send a patient's blood sample to a location where a large number of other samples are being sent raises the obvious 30 possibili~ that the patient's sample will become lost or incorrectly identified. Under these circumstanees, an abnorrnali;y in the patient's blood could become misidentified with ano~her patient so that the abnormali~ would go untreated. Also, the patient could receive treatment indicated by a lab report resulting from tests on another patient's blood, 35 and such treatment would be wasteful and possibly harmful.

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The disadvantages of the above, commonly used lab test procedures extend not only to the manner in which the blood samples are processed but also the manner in which the blood samples are handled and transported. ~he patient's blood sample can contaminate the health care S practitioner or lab technician when the blood sarnple is being transported tO
the lab or transferred from the syringe or test tube to another container or to the instrument for analysis.
Additionally, current blood test procedures also provide an avenue for various errors or inaccuracies to enter into the testing 10 procedure. For example, blood can be transferred from the syringe or test tube into a container that ha3 been improperly or insufficiently cleaned. As a result, the blood sample can become contaminated with residue left in the container, thereby affecting the accuracy of tests perfonned on the sample.
The blood sample can become contarninated upon exposure to air during lS this transfer as well. Although laboratory procedures have been designed to rninirnize this problem, any exposure to air during the ~ransfer of the sample from the original collection container to a subsequent container or an analyzer may affect the accuracy of the analysis. Contarninants can also be present in the chemical analysis instruments that process the blood 20 sample since the sample comes into contact with the same tubes, valves, pumps, etc., that the blood samples of other patients contact. In fact, it is quite comrnon for deposits to build up in the flow path of the analysis instrument especially in valves and pumps. These deposits provide a ready vehicle for the growth of bacteria and the retention of blood samples or 25 calibrating fluids from on~ sample to the next. Deposits on such components as valves can also cause them to stick either open or shut.
While such flow path components as tubing, valves and pumps can be replaced whenever deposits start to build, ~requent replacement of such components can be very expensive. ll~e need to frequently monitor the 30 condition o~, and replace the components of, conventional blood chemical analyzing instrurnents can also be very time-consuming and thus diverts the attention of the health care practitioners from the care of patients.
To maintairl and verify the accuracy of the analysis instruments can also be very time-consuming. Sensitive analysis 35 instruments must be calibrated with numerous fluids and/or precision m~xed gases at frequent intenals. To verify accuracy of calibration, samples 2~37~

with known results are frequently analyzed and the result recorded for statistical tracking. The calibration and verification procedures consume considerable additional time and require skilled operators. Considerable volumes of fluids and/or precision mLxed gases are required to perform 5 these operations. Since the flow path of these instruments can contain residual deposits from patient blood samples, all fluids utilized by the analyzer must be considered contam~nated and be handled with as much cau~ion as the original patient sample. Should any par~ of this calibration and verification process be skipped or perforrned incorrectly, the results 10 could contain errors or inaccuracies that rnight adversely a~fect patient care.
Most of the above-described problems of cvnventional testing procedures could be eliminated if the blood sample was analyzed using a disposable device and an instrument located at the patient's bedside.
However, bedside blood analysis was heretofore thought not to be practical 15 because the high cost and large size of convention~l blood analysis instrurnents and associated fluid and/or gas containers prevented them from being either disposable or sufficiently portable to be effectively used at the patient's bedside.
Efforts have been made to simplify and miniaturize 20 conventional analyzers by providing conventional analyzers with a disposable cartridge. The c~rtr~dge maintains the level of the analyzing fluids in the analyzPr znd provides a waste container for the waste analyzing fluids and blood. While such arrangement does simplify the analyzing procedure, the disposable cartridge is extremely expensive, making the 25 device commercially impractical. Moreover, as with the conventional analyzer described above, a pumping system is required in the analyzer to pump the blood and analyzing fluids through the device, thereby adding both size and weight to the analyzer.

30 Summarv of the Tnvention It is an object of the invention to provide a dispos~ble blood sampling cartr~dge that also contains various fluids used in analyzing the blood.
It is another object of the irmention to provide a disposable 35 blood sampling cartridge that allows a blood sample to be analyzed in a 20~70~

manner that min n~izes the dangers of contaminating the blood sample or medical personnel performing the analysis.
It is another object of the invention to provide a disposable blood sampling sartridge that allows the sa~e and easy disposal o~ the waste 5 blood and other fluids used in the analysis.
It is another object of the illvention to provide a disposable blood sampling cartridge that is capable of collecting venous blood w~thout the use of a syringe.
It is another object of the invention to prov~de a device for 10 collecting body fluids in a manner which does not require transfer from a collection device to another container in order to be analyzed.
It is still another object of the invention to provide a disposable blood sampling cartridge that forces collected blood, analyzing fluids and waste fluids through an analyzing device thus allov.~ng the 15 analyzing device to dispense w~th an expensive and difficult to clean t1uid pump.
It is a further object of the invention to prov~de a disposable blood sampling cartridge that allows a blood sample analyzer to be inexpensive, compact and simple to use thereby making bedside blood 20 analysis feasible.
These and other objects of the invention are provided by a disposable blood sampling cartridge for use with a blood sample analyzer.
The blood sampling cartridge contains a blood reservoir having a first port adapted to cornmunicate with a hypodermic needle. The cartridge also 25 includes a waste cnllection chamber adapted to receive waste fluids from the blood sarnple analyzer, and a plurality of ampules each cont~ining a respective fluid adapted for use by the blood sample analyzer. The cartridge is used by ~irst inserting the hypodermic needle into a patient's artery or vein, and then drawing blood from the patient into the blood 30 reservoir. The disposable blood sampling cartndge is then connected to the blood sample analyzer, and the blood is expelled from the reservoir into the analyzer. After the blood has been analyzed, it is transferred to the waste colle tion chamber in the cartridge. E~ach of the fluids in the blood collection cartridge are then expelled into the blood sample analyzer for 35 use by the blood sarnple analyzer. After use, each of tbe fluids are also ~ransferred to the waste collection chamber in the cartridge.

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The blood reservoir in the cartridge is preferably vented through a port which is blocked by an air-permeable, blood-impermeable material so that blood flowing into the blood reselvoir can displace air in the chamber through the rnaterial until the reservoir has been filled with 5 blood. The cartridge preferably includes a piston ~hat is movable into the blood reservoir to force blood out of the blood reservoir when the blood is to be analyzed. The piston is actuated externally through an aperture in the cartridge at one end of the cartriclge. A plurality of ampules containing respe~ive fluids used by the blood sarnple analyzer are also preferably 10 accessible at the end of the cartridge containing the aperture. I~e fluid in the ampules are accessed through a frangible portion of a wall of each ampule that facing the end of the cartridge containing the aperture. As a result, the fluids in the ampules may be accessed by puncturing the ampules from the same end of the cartridge through which the piston is actuated~
The disposable blood sampling cartridge rnay include an evacuated container which is selectively coupled to the blood rese~voir to draw blood into the blood reservoir thereby allowing the cartridge ~o be used for collecting venous blood. The evacuated container is preferably fabricated from a frangible material which is fractured by asl externally 20 accessible resilient tab positioned adjacent to the evacuated container thereby coupling the vacuum in the evacuated container to the blood resen~oir. The tab may be forced inwardly by inserting the cartridge in a needle adapter containing a double-ended needle thereby causing the tab to *acture the evacuated container when one end of the needle is inserted 25 into the blood reservoir and the other end of the needle is inserted into the vein of a patient.
Alternatively, the disposable blood sampling cartridge may include an evacuated cylinder having a puncturable septum at each end.
The septum at one end is punctured by a needle adapter to draw blood into 30 the evacuated cylinder. After sufficient blood has been drawn into the cylinder and the needle adapter has been removed~ it ;s connected to a blood sample analyzer. The analyzer includes a hypodermic needle that punctures the septum through which the sample was taken to gain access to the interior of the evacuated cylinder. A second hypodermic needle 35 mounted on a push rod in tbe cartridge is then actuated by an external actuating rod to puncture the septum at the opposite end of the evacuated 7 2~7~

cylinder. The point of the second needle is embedded in a breakaway piston positioned in the cylinder. As the push rod advances, the piston is pushed along the cylinder to force the blood out of the cylinder and into the analyzer. l'hereafter, the second needle is pushed all of the way through S the ~reakaway piston. ~he second needle has an outlet positionecl in a waste collection chamber in the cartridge. The needle thus allows communication between the cylinder and the waste collection chamber.
A~fter the blood has been analyzed, i~ is forced into the waste collection chamber by analyzing fluids flowing from a plurali~y of ampules in the 10 cartridge into the blood sample analyzer in the opposite ~irection. Spent analyzing fluids are also directed to the waste collection chamber in the same manner.

Brief l~)escription of the Dra~ng~
Figure lA is a cross-sectional view of the preferred embodiment of the inventive blood sarnpling cartridge used ~or sampling arterial blood.
Figure lB is a cross-sectional view of the blood sampling cartridge of Figure lA taken along the line 1B-1B of Figure lA.
Figure 2 is a cross-sectional v~ew of the blood sampling cartridge of ~igure 1 conEigured for taking a blood sample.
Figure 3 is a detailed cross-sectional view of a portion of the blood sampling cartridge of Figure 1 showing how an internal blood rese~voir is vented during the blood collection process.
Figure 4A is a cross-sectional view of the preferred embodiment of the inventive blood sampling cartridge used for sampling venous blood.
Figure 4B is an end elevational v~ew of the venous blood sarnpling cartridge of Figure 4A.
Figure 5 is a det~iled cross-sectional view of a portion of ~he venous blood sarnpling cartridge of Figure 4 showing how a vacuum draws blood into an internal blood reservoir during the blood collection process.
~igure 6 is a cross-sectional v~ew of the venous blood sampling car~ridge of Figure 4 corlfIgured for taking a blood sample.

- ~ -Figure 7 is a cross-sectional view showing the mamler in which blood collected in the cartridges of Figures 1 and 4 are transferred into an external blood analysis device.
Figure 8 is a cross-sectiorlal view showing the manner in S which various fluids stored in the cartridges of Figures 1 and 4 are transferred into an exter~al blood analysis device.
Figures 9A-D are cross-sectional views showing how fluids in respPctive ampules contained in ~he blood s~npling cartridges of Figures 1 and 4 are accessed.
Figure 10 is a detai}ed cross-sectional view of a portioll of the blood sampling cartridge of Figures 1 and 4 show~ng the manner in which waste blood and fluids flow into an internal waste collection chamber in the cartridge.
Figure 11 is a cross-sectional view of an alternative lS embodiment of the inventive blood sampling cartridge used for sampling venous blood.
Figure 12 is a cross-sectional view showing the manner in which venous blood collected in the cartridge of Figure 11 is transferred into an external blood analysis device.
Figllre 13 is a cross-sectional view showing the manner in which various fluids stored in th~ cartridge of Figure 11 is transferred into an external blood analysis device.
Figure 14 is an isometric view of still another embodimene of the inventive disp~sable blood sampling cartridge shown with its internal 25 rotary valve in the 0 position.
Figure 15 is a cross-sec~ional view of the disposable cartridge taken along line 15-15 of Figure l".
Figure 16 is a schematic, cross-sectional view of the disposable cartridge taken along line 16~16 of Fi~ure 15.
Figure 17 is a cross-sectional view of the disposable cartridge taken along line 17-17 of Fi~ure 15 shown with its internal rotary valve in the 60 position.
Figure 18 is a schernatic, cross-sectional view of the disposable cartridge takerl along line 18-18 of Pigure 17.

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Figure 19 is a cross-sectional view of the disposable cartridge taken along line 19-19 of Figure 14 shown with its in~ernal rotary valve in the 120 position.
Figure 20 is a schematic, cross-sectional v~ew of the 5 disposable cartridge taken along line 2~20 of Figure 19.
Figure 21 is a schematic, cross-sectional view of the disposable cartridge taken along line 21^21 of Figure 14 shown with its internal rotary valve in the 180 pOsiti3il.
Figure 22 ;s a schematic, cross sectional view of the 10 disposable cartridge taken along line 22-~2 of ~igure 14 shown with its internal rotary valve in the 240 position.
Figure 23 is a schematic, cross-sectional view of the dlsposable cartridge taken along line 23-23 of Figure 14 shown with its internal rotary valve in the 300 position.
r)etailed l:)escri~jQ~of the Invention One embodiment of the inventive disposable blood sampling cartridge 10 is illustrated in Figures lA and lB. The cartridge 10 illustrated in Figures lA and lB is specifically adapted to sample arterial blood. The 20 cartridge 10 includes a generally cylindrical llousing 12 having a generally planar end wall 14. A cylindrical boss 16 formed at the opposite end of the housing 12 is adapted to receive a hypodermic needle (not shown).
However, during shipment and storage, the boss 16 is covered by a septum eap assembly 18. l~he septum cap assembly 18 includes a plastic cap 19 25 surrounding a resilient insert 21. The plastic cap 19 has a cylindrical portion 23 that fits over the boss 16.
The boss 16 defiIIes a ~luid port 20 communicating wi~h a blood reservoir 22. The end of the blood reservoir 22 opposite the port 20 is closed by a piston 24 mounted at the end of a push rod 26. The opposite 30 end of the push rod 26 includes a push rod clip 28 for releasably securing anactuating rod (not shown) extending through an aperture 30 in the end wall 14. The portion of the housing 12 surrounding the push rod 26 forms a waste collection chamber 32 which, as explained below, is used to coilect waste fluids after the blood alla!ysis has been completed. The housing 12 35 also contains a plurali~ of ampules 40 each of which contains a respe~tive fluid that is used by an external blood sample analyzer. A pis~on 42 is 20~705 formed at the end of each ampule 40 for expelling the fluid, as explained below.
The blood sampling cartridge 1û is shown in Figures 2 and 3 in its configuration for taking a blood sample. With reference to Figure 2, 5 the septurn cap assembly 18 (Figure lA) is removed from the boss 16 and a conventional hypodemlic needle 50 is placed over the boss 16 in the same maTmer as the septum cap assembly 18. With reference also, now, to ~igure 3, the piston 24 is placed in a position so that it blocks communieatior between the blood reservoir æ and the waste collection chamber 32. The 10 piston 24 separates the blood reservQir 22 from the waste collection chamber 32 by virtue of the contact between the piston 24 and divider 54.
However, the placement of the piston 24 forms a passage ~6 arou~ld the piston 24 and through an opening 58 into the waste collection chamber 32.
An air-permeable, fluid-impermeable rnembrane 6û is placed over the lS opening 58. As a result, when blood is forced into the blood reservoir 22 by arterial pressure, air in the blood reservoir 22 is vented through the passage 56 in opening 58 until the blood reservoir 22 has been filled with blood.
The fluid-impermeable membrane 60 then prevents the blood from flowing from the blood reservoir 22 to the waste collection chamber 32. Once the 20 blood reservoir æ has been filled with blood, the cartridge 10 is ready to beconnected to an external blood sample analyzer which analyzes the blood in the blood reservoir 2~.
7 As mentioned above, arterial blood is forced into the blood reseIvoir 22 in the embodiment of Figures 1-3 because the pressure of the 25 blood in the arteries are greater than atmospheric pressure. However, the pressure of blood in veins, ie., venous blood, is not sufficient to force venous blood into the blood reservoir 22. The disposable blood sampl;ng cartridge 70 of Figures 4-7, which is substantially the same as the arterial sampling cartridge 10 of Figures 1-3, can be used to obtaill samples of 30 venous blood. Thus, for the sake of brevity, identical components have been provided wi~h identical reference for both embodiments, and an explanation of their structure and operation will not be repeated. The venous blood sampling cartridge 70 of Figures 4-7 differs from the arterial blood sampling cartridge 10 shown in Figures 1-3 in two respects. First, its 35 blood reservoir 22 is covered by a cap 72 made of a resilient material such as rubber. As explained below, the resilient composition of the cap 72 2~7~

allows it to be punctured by a needle and causes it to be self-sealing when the needle is withdrawn. The second difference between the venous blood sampling cartridge 70 and the arterial blood sampling cartridge 10 is that the venous blood sampling cartridge 70 utilizes a vacuum to draw blood 5 into the blood reservoir 22. Specifically, the venous blood sampling cartridge 70 contains a tube 80 made of a frangible material such as glass.
The tube 80 is evacuated, and it is positioned within an airtight compartment 86, as best illustrated ill Figure 5. l~e airti~ht compartment 86 communicates w~th the blood reselvoir 22 through an opening 88 and an 10 air-permeable, fluid-impermeable membrane 60. Blood is drawn into the blood reservoir 22 of the venous blood sarnpling cartridge 70 by piercing the resilient cap 82 with a needle alld thesl breaking the frangible tube 80, thereby coupling the vacuum in the tube 8û to the blood reservoir 22 through the opening 88. The vacuum draws blood into the blood reselvoir 15 22 until the blood reservoir 22 is filled, at which point the fluid-imperrneable membrane 60 prevents further blood from entering the reservoir æ.
Although any suitable means rnay be used to pierce the cap 72 and break the tube 80, a needle adapter 90 illustrated in Figure 6 is 20 preferably used to perform both functions. The needle adapter 90 is ~ormed of a rigid material, such as plastic. The needle adapter 90 has a cylindrical portion 92 hav~ng an outwardly extending radial flange 94 at one end and an end cap 96 forrned at the opposite end. The end cap 96 carries a double-ended hypodermic needle 98, the inner end of which extends 25 through a resilient seal 100. The inside diameter of the cylindrical portion 92 is just slightly larger than the ou~side diameter of the housing 12. AS a resuit~ when the cartridge 70 is inserted into the needle adapter 90, as illustrated in Figures 6, the inner portion of the needle 9S pierces the resilient cap 72. At the same time, the flanged end of the adapter 90 pushes 30 a tab 102 inwardly against the frangible tube 80, thereby fracturing the tube 80 and releasing its vacuum to the blood rPservoir 72.
In practice, the cartridge 70 is not inserted into the needle adapter 90 a sufficient distance to depress the tab 102 until the folward end of the needle 98 has been placed in the vein of a patient. Once the needle 35 98 is in place, the cartridge 70 is inserted further into the needle adapter 90 to depress the tab 102 to break the tube 80 and draw blood from the vein ` "

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into the blood reservoir 22. Once the blood has been drawn into the blood reservoir 2Z, it is processed in the same marmer as the blood in the arterial blood sampling cartridge 10 is processed.
The housing 12 surrounding the bloocl reservoir 22, as well as 5 the blood reservoir 22 itself, is preferably made ~rom a transparent material, such as glass or clear plastic. As a result, the medical practitioner taking the blood sample can view the blood flowing into the blood reservoir Z. Also, the blood reservoir 22 preferably contains an anticoagulating agent, such as hepann, to prevent the blood sample from coagulating in the 10 blood reservoir æ.
Although the various embodiments of the inventive disposable blood sampling cartridge have been described as using a hypodermic needle inserted into a blood vessel to obtain blood samples, it will be understood that other devices may be used. For example, a 15 hypodermic needle may be inserted into a catheter inserted in a blood vessel, a conduit delivering blood to a hemodyalysis de~ce, an arterial line, etc.
The disposable blood sampling cartridge 10 is coMected to a blood sample analy~er, such as a flow cell 110, as illustrated in Figure 7. It 20 will be understood, however, that other embodiments of the inventive blood - sample cartridge, including the cartridge 70, are cormected to the flow cell 110 in the same malmer. Fluid can flow through the flow cell 110 in either direction through first and second conduits 112, 114. Each of the conduits 112, 114 tern~inate in respective hypoderrnic needles 116, 118, respectively.
T~ié blood sampling cartridge 10 is connected to the flow cell 110 with the needle 116 extending through the resilient insert 21 of the septurn cap assembly 18 (or cap 72 of the venous blood sampling cartridge 70) and into the blood reservoir 22. The eartridge 10 is rotated so that the waste area 32 is opposite the needle 118 of the conduit 114, and Lhe needle 118 is therl inserted through the end 14 of the housing 12 into the waste area 32. An actuating rod 120, which may be a par~ of the blood sample analyzer, is then inserted through the aper~ure 30 in the end wall 14 to engage the clip 28 at the end of the push rod 26. The actuating rod 12Q
then forces the push rod 26 forwardly so that the piston 24 is pushed into 35 the ~blood reservoir 22. The piston 24 forces blood from the blood reservoir 22 through the conduit 112 into the flow cell 110. The blood flowing into .

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the flow cell 110 displaces any analyzing fluid still in the flow cell 110 from a previous test. This remair~ng analyzing fluid flows through conduit 114 into the waste collection chamber 32. A small air bubble, which naturally occurs as the needles 112, 118 are inserted and removed from the cartridge 5 1û, is introduced ahead of the blood, and aids in maintaining the separation between the blood and the analyzing fluid left from the previous test. The bubble thus prevents the blood from mixing with the fluid.
When the actuating rod 120 has reached the end of its travel, the flow of blood from the blood reservoir 22 tenminates and the flow cell 10 110 analyzes the blood. After the analysis has been colnpleted by the flow cell 110 in a conventional marmer, the needle 118 is withdrawn from the end wall 14 of the cartridge 10, and the cartridge 10 is ro~ated to the position shown in Figure 8. In this position, the needle 118 is inserted through the end wall 14 of the housing into one of the ampules 40 15 contained within the housing.
The end wall of the ampule 40 may be broken and the analyzing fluid extracted by any suitable means. However, in the p}eferred embodiment, the technique illustrated in Figure 9 is used. Specifically, as shown in Figure 9A, the arnpule 40 containing analyzing fluid 130 has its 20 internal piston 42 positioned against an end wall 132 having a thinned portion 134. As shown in FigQre 9B, the needle 1~8 includes a hollow inner needle 140 and an outer sleeve 142 slideably mounted on the inner needle 140. The sleeve 142 i5 pushed against the thinned portion 134 of the end wall 132 in order to crack the thinned portion 134 as illustrated in Figure 25 9B. The inner needle 14û is then pushed through the piston 42 as illustrated in Figure 9C. Finally, the inner needle 140 and outer sleeve 142 are advanced into the ampule 40 together, thereby driving the piston 42 further into the ampule 4û. Movement of the piston 42 displaces the fluid 130 into the inner needle 140 and on the conduit 114 to thP flow cell 110 as 30 illustrated in Figure 8.
Although the flow cell 110 has been described as using a needl~ 118 having an inner needle 140 and an outer sleeve 142 to puncture the ampules 40j other devices can be used. For exa~nple, a pointed rod may be used to puncture the arnpule 40, and a separate hollow needle may be 35 used to draw analyzing fluid from the ampules 40.. Also, an ampule having a resilient, easily punctured end wall may be used.

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Returning IIOW to Figure 8, as the piston 42 is pushed into the ampule 40, the actuating rod 120 pulls the push rod 26 rearwardly until thP
piston 24 has been withdrawn to the position illustrated in Figure 8. The actuatirlg rod 120 is then pulled from the clip 28 and out of the aperture 30, 5 as illustrated in Figure 8. As the piston 24 is pulled out of the blood reservoir 22, it creates a suction in the blood reservoir 22 that aids in withdrawing the sampled blood from the flow cell 110 to the conduit 112.
The fluid flowing into the flow cell 110 through the conduit 114 also, of course, forces the analyzed blood ollt of the tlow cell 110. When the piston 10 24 has been fully retracted, it allows free communication between the blood reservoir 22 and the waste collection chamber 32, as illustrated in Figure 10. Specif~cally, when the piston 24 has been fully retracted, its side walls no longer make contact with the divider 54, as illustrated in Figure 3.
Consequently, fluid can flow from the blood reservoir æ into the waste 15 collection chamber 32 around the piston 24 through path 150. As also illustrated in Figure 10, the push rod 26 has formed therein an outwardly extending tab 152 which is captured by an inwardly extending ring 154 mounted at the end of a resilient finger 156 when the push rod 26 is in the position illustrated in Figure 3. Withdrawal of the push rod 26 to open the ~0 path 150 between the blood reservoir 22 and the waste collection chamher 32 requires that the projection 152 displaces the ring 154. The projection 152 and ring 154 thus provide a detent for preventing the path 150 between the blood reservoir 22 and waste collection 32 from being inadvertently opened.
Once the path 150 has been opened, the analyzed blood can I1OW from the blood reservoir 22 into the waste collection chamber 32. The analyzing fluid extracted from the ampule 40 then flows into the aOw cell 110 through the conduit 114. When 211 of the fiuid 130 has been removed from the ampule 40, the needle 118 is withdrawn from the housing 12. The cartridge 10 is then rotated until the needle 118 is positioned behind another arnpule 40. The procedure shown in Figare 8 is then repeated to cause the fluid from the next ampule to flow through condui~ 114 into the flow cell 110~ thereby forcing the previously withdrawn fluid into the waste collection chamber 32 through the needle 112, blood reservoir 22, and path 150. Fluid is withdrawn from each of the ampules in the same manner until the blood sample analyzer has completed its analysis.

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~s is well known in the art, blood sarnple analyzers, such as the flow cell 110 illustrated in Figure 8, utilizes several fluids for performing such functions as calibrating the ur~it and washing the unit to prevent contamination from prior salibrating fluids and blood samples.
After the analysis has been completed, the needles 11~, 118 are withdrawn frorn the cartridge 10 and the cartridge 10 is discarded.
Significantly, all of the waste products from the analysis are also discarded with the cartridge 110.
An alternative embodiment of a venous blood sampling cartridge 170 is illustratPd in Figures 11-13. As with the previously explained embodiments, the cartridge 170 includes a housing 12 containing a plurality of fluid ampules 40 which are accessed through the end wall 14 of the housing 12. However, the venous blood sampling cartridge 170 illustrated in Figures 11-13 contains an evacuated blood collection tube 172 having septums 174, 176 at opposite ends and a breakaway piston 178 of the same type 42 used in the ampules 40, as explained above. The cartridge 170 also utilizes a push rod 180 having a clip 28 forrned at one end adjacent in aperture 30 in the end wall 14. However, a hypodern~ic needle 182 projects from the opposite end of the push rod 180.
The blood sampling cartridge 170 is used to take a sample of venous blood in substantially the same manner as the previousIy desrribed venous blood sampling cartridge 70 explained above with respect to Figure 6. Specifically, a needle adapter having a double-ended needle is placed in the vein of a patient and then pierces the septum 174 of the blood collection tube 172. The vacuum in the tube 172 then draws venous blood into the tube 172. When sufficient blood has been drawn into the tube 172~
the double~ended needle is pulled out of the blood vessel and out of the septum 174.
The tube 172 is pre~erably formed from a transparent mater~al, such as glass or transparent plastic, so that the person taking the sample can determine when it has received sufficient blood. Also, the tube 172 preferably contains an anti-coagulating agent.
After the blood sample has been taken, the cartridge 170 is connected to a blood sample analyzer, such as a comentional flow cell 110 35 as illustrated in Figure 12. ~s with the previously explained embodiments, the flow cell 11û includes a needle 112. The needle pierces the septum 174 2~7~

while the needle 118 at the end of the conduit 114 is inserted through the end wall 14 of the cartridge 170 into a first waste collection area 192. The actuating rod 120 is then inserted through the aperture 30 and into the clip 28 of the push rod 180. The actuating rod 120 advances the push rod 180, S thereby driving the needle 182 through the septum 176 and into the breakaway piston 178. However, the breakaway septum 178 has sufficient resistance to puncture that the needle 182 slides the piston 178 along the blood collection cylinder 172 rather than puncturing the piston 178. As the piston 178 slides along the blood collection tube 172, it forces ~he blood in 10 the tube 172 into the flow cell 110 which, in turn, forces fluids from a previous test through the conduit 114 in needle 118 into the waste collection chamber 192.
When the piston 178 has reached the opposite end of the tube 172, all of the blood has been ejected from the tube 172 and further 15 movement of the piston 178 is not possible. As the push rod 180 is advanced further, the needle 182 is pushed all the way through the piston 178, as illustrated in Figure 13. The needle 118 is then withdrawn from the waste collection chamber 19~ and inserted into one of the ampules 40, as expla~ned above with reference to Figure 8. The needle 118 includes a port 20 196 which opens into a second waste collection chamber 198. The needle 118 is then in communication with the needle 112 so that analyzed blood and used analyzing iluids flow from the flow cell 110 and conduit 112 through the needle 118 and out port 196 into the second waste collection chamber 198. After all of the ampules 40 in the cartridge 170 have been 25 emptied as described above, the needles 112, 118 are removed from the cartridge 170 and the cartridge 170 is discarded.
As shown in Figure 14, an alternative embodiment of a disposable arterial blood sampling c~rtridge 200 including front 202 and rear 204 cylindrical portions. A needle 206 projects from the front portion 3û 202, and the front and rear portions 2027 2W, respectively, are rotatable with respect to each other. A cap 208 is also shown for covering a blood inle~ 210 of the fron~ portion after the blood has been ~nthdr~wn and the needle removed. ~ explained below, rotation of the front and rear po~ions 202, 204 with respect to each other between each of several 2~7~

discrete positions controls:
(a) the llow of blood (i) through the needle 206 into the front portion 202;
5(ii) from the front portion 202 to a flow cell 212 through an outlet port 214; and (b) the :aow of w~te blood, calibrating, control and washing flu;ds from respective reservoirs in the rear portioll 204 to the flow cell 212 through the outlet port lû214 and into the waste chamber in the front por~ion 202.
The flow cell 212 is of conventional dçsign and, taken alone and apart from the blood sampling device 200, is not considered to be inventive.
15Referring also now to Figure 15, the front portion 202 includes a blood reservoir 216 colmected to the needle through the blood inlet 210, a piston receiving portion 218, an annular waste chamber Z20, a vent line 222 communicating with the waste chamber, and cartridge outlet and inlet ports 214, æ4, respectively. The ports 214, 224 are normally 20 closed by a cover 226 that projects forwardly frorn the rear portion 2~.
The blood reservoir 216, vent line 222 and cartridge outlet port 214 each have a longitudinal portion which communicates with a rear face 228 of the front portion 202. In particular, the blood reservoir ~16 is disposed directly on the long~tudinal axis of the front portion 202 while the vent line 222 and 25 c~ridge outlet port 214 are radially displaced from the longitudinal axis by an equal distance. Th~ needle unit 230 includes a needle 2û6 a~ well as a needle attaching portion 232. Th needle attaching portion 232 is designed to be slid onto one end of the tubular portion 234 of the piston unit 236 such that the drive hex 238: circumscribes the needle attaching portion in 30 the manner illustrated in Figure 15.
Referring also to Figure 16, the vent line 22? has a vent 240 :: disposed thereiII which per3nits air to pass therethrough while preventing the passage of blood. Natural venting is provided through the cartridge inlet port 224 when 'Dlood is withdra~vn: and through the vent line 222 when : 3S wastefluidsareintroducedmtothewas~echamber220.

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The rear portion 2~ is also ~lindrical in shape and has a diameter slightly larger than the diameter of th~ front pOrtiOQ 21)2. In this manner, a front end of the rear portion 204 is rotatably disposed over the rear end of the front portion 202 such that the front face 242 of the rear 5 portion abuts against the rear ~ace 228 of the front portion 202, as illustrated in Figure 15. A groove 244 is providecl on the front face 242 of the rear portion. The groove 244 extends radially from the center of the face, terminating short of ~he outer circun~erence of the rear portion 204.
l'he groove is designed to interconnect the blood reservoir 216 of the front 10 portion 202 to either the vent lîne 222 (Figures 16 and 17) or the cartridge outlet port 214 by rotatirlg the front por~ion 202 relative to the rear portion 204, as will be described in detail below.
The piston unit ~36 includes an axially extending tubular portion 234, flange 246 and drive hex 238, as illustrated in Figure 16. The 15 tubular portion 234 de~lnes the blood inlet 210 which commurLicates with the blood reservoir 216 of the front portion 202. The tubular portion 234 is telescopically disposed in the bore forming the blood reservoir while the flange 246 is slidably disposed in the p}ston receiving portion 218 of the front portion. The piston unit 236 is actuated to expel blood from the blood 20 reservoir 216, as described in detail below.
As illustrated in Figure 19, the cartridge outlet port 214 is substantially L-shaped having the above-described longitudinal portion 24~
as well as a radially extending portion 250 which extends to the outer circumference of the ~ront portion. The cartridge inlet port 224 also 25 exterlds in the radial direction and con~nunicates with the waste chamber 22Q The inlet port æ4 is disposed adjacent the outlet port 214 allowing convenient access of the flow cell to the ports.
With reference to Figures 15 and 16, the rear portion 204 includes ~our axially extending ampule ports 252 and a corresponding 30 number of ampule receiv~ng bores 25~i. Each of the ampules 256 includes a srnall diameter stem pottion 258 and a large diam ter base portion 260.
The ampules are respectively disposed in the ampule receiving bores by respectively inserting the small diameter portions in the ampule ports.
Each of the ampules contains a different analyzing fluid: wash~ calibrant 1, 35 calibrant 2, an~ control. The anal~zing fluids are utilized to wash, calibrate, and flush the flow cell 212 during the blood analysis. The ampule ports ~5~

2~7~

communicate w~th the front face 242 of the rear portion 2W and are sequentially aligned with the longitudinally disposed portion 248 (Figure 20) of the cartridge outlet port 214 such that the ampule fluids can be individually introduced into the aOw cell ~12 by successively rotatin~ the 5 front portion with respect to the rear portion of the device a predetermined number of degrees.
Each of ~he ampules 256 has a ball 262 which acts as a piston to pump the fluid therefrom. Specifically, as illustrated in Figure 19, the rear of each ampule is fractured using push rod 264 enabling the push rod 10 264 to slide the ball in the direction of the ampule stem 258, as i11ustratedby the arrow. In this manner the fluids are pumped from the ampules into the flow cell via the arnpule ports 252 and the outlet port 214.
The volume of the blood reservoir is relatively small so as to miniIl~ze the amount of blood withdrawn from the patient.
15 Correspondingly, the passages in the car~idge are designed to be reLItively short in length and small in diameter to insure that a minimal amount of blood is lost when the blood flows into the flow cell so that there is a suf~lcient amount of blood in the flow cell for analysis. Additionally, the front portion 202 may be manufactured out of a transparent rnaterial to 20 permit the user to view the amount of blood in the reservoir. Finally, an absorbent material may be packed in the waste chamber to absorb the w~ste fluids.
The operation of the device is as follows. Initially, the front por$ion 202 and rear portion 204 are rotatably aligned in the manner illustrated in Figures 14, 13 and 16 with the cover 2~6 blocking the flow cell ports 214, 224. For explanation, this position will be referred to as the 0 position. In the 0 position, blood is withdrawn from the patient's artery, relying on the arterial pressure to force the blood into the device. As illustrated in Figures 15 and 16, the blood reservoir 216 of the front portion 202 is connected to the vent line 2æ via the groove 244 for perrnitting the air in the blood inlet to be vented through the waste chamber 220 so as to allow the blood to enter the device. Once the flow of blood reaches the vent 240 provided at the inlet to the ven~ line 222 the flow of blood from the patient's artery stops.
Thereafter, the needle is withdrawn from the patient, removed from the device and a luer lock cover 20g (Fi 3ure 17) secured to ` , 2~7~

the front end of the piston unit 236. The device is then placed in an analyzer having a flow cell 212 (Figure 14). The analyzer rotates the rear portion 204 of the device approximately 40 u~;th respect to the fron~
portion 202 to expose the flow cell ports 214, 224. At this position, the flow S cell 212 in the analyzer is mated to the outlet aLnd inlet ports 214, 2~4, respectively. Thereafter, the rear portion is rotated an additional 20 to the 6û position to align the groove 244 with the longitudinal portion 248 of outlet port 214, as illustrated in Figures 17 and 18. In this position, the blood reser~oir 216 comrnulucates with the outlet port 214 through the 10 groove 244, longihldinal portion 248 and radially exterlding portion 250. At this time, the analyzer slides the piston unit 236 in the direction of the arrow of Figure 17 a predetermined distallce causing the blood in the blood reservoir 216 to be introduced into the flow cell. Thereafter, the blood is analyzed.
After the blood has been analyzed, the analyzer rotates another 60 to the 120 position, as illustrated in Figures 19 and 20. In this position, the ampule port 252 for the wash is aligned with the longitudinal portion 248 Oe the cartridge outlet port 214. At this time, a mechanism in the analyzer fractures the stem 258, the push rod 264 in the analyzer 20 fractures the base of the ampule and, thereafter, the push rod 264 pushes the piston ball 262 in the direction illustrated by arrow B in Figure 19 forcing the wash fluid frorn the ampule and into the flow cell 212. The wash fluid thereby flushes the blood from the flow cell through the cartrid"e inlet port 224 and into the annular waste charr;ber 220. Thereafter, the rear 25 portion 204 is rotated another 60 to the 180 position, illustrated in Figure 21, aligning the calibrant 1 ampule port 252 with the longitudinal portion 248 of cartridge outlet port 214. Again, the ampule stem and base are fractured and the calibrant 1 fluid forced into the flow cell to calibrate the analyzer and flush the wash fluid from the flow cell and into the waste 30 chamber 220. These steps are repeated for the calibrant 2 ampule at the 240 position (Figure 22) and the control ampule ~t the 300 position (Figure 23). Finally, after the control fluid has been introduced into the flow cell 212, the analyzer rotates the rear portion another 200 to the 3200 position and detaches the cartridge from the flow ~ell. Thereafter, the ~5 anal~zer rotates the rear portion ano~her ~ to the initial 0 position such that the cover 268 of the rear portion 204 closes the flow cell ports 214, 224, 2~5~7~

as illustrated in Figures 14 and 16. The device can then be disposed of without the user ever con~acting the blood or any of the fluids.
While the vanous embodiments o~ the invention have been described w~th the disposable cartridge storing four ampules, it is 5 understood that the cartridge could store fewer or more ampules as required. Moreover, while tbe various embodiMeIlts of the disposable c~ridge are shown connected to a flow cell for analyzing blood, it is understood that the cartridges could be used to obtain samples of other body fluids, which would then be analyzed by analyzers other than flow cells 10 or other types of blood sample allalyzers.

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Claims

1. A method of analyzing a body fluid of a patient using a body fluid analyzer and a disposable sampling cartridge containing a waste collection chamber, and at least one analyzing fluid adapted for use by said body fluid analyzer, said method comprising:
drawing a body fluid from the patient;
delivering said body fluid to said body fluid analyzer;
analyzing said body fluid in said body fluid analyzer;
connecting said disposable sampling cartridge to said body fluid analyzer before or after delivering said body fluid to said body fluid analyzer;
after analyzing said body fluid, conveying said body fluid from said body fluid analyzer to said waste collection chamber;
expelling said analyzing fluid from said sampling cartridge into said body fluid analyzer for use by said body fluid analyzer before or after delivering said body fluid to said body fluid analyzer;
conveying said analyzing fluid from said body fluid analyzer to said waste collection chamber after said body fluid analyzer has used said analyzing fluid; and disconnecting said sampling cartridge from said body fluid analyzer.

2. The method of claim 1 wherein said method of drawing a body fluid from the patient includes the step of drawing said body fluid into a body fluid reservoir contained in said sampling cartridge, and wherein said step of delivering said body fluid to said body fluid analyzer includes the step of expelling said body fluid from said reservoir into said body fluid analyzer.

3. The method of claim 2 wherein said cartridge includes an externally actuatable piston extending into said reservoir, and wherein said body fluid is expelled from said reservoir by forcing said piston into said reservoir.

4. The method of claim 3 wherein said body fluid is conveyed from said body fluid analyzer back to said sampling cartridge by drawing said piston out of said reservoir, thereby creating a suction in said reservoir.

5. The method of claim 2 wherein said cartridge includes an evacuated container positioned within said cartridge, and wherein said body fluid is drawn from the patient into said reservoir by selectively coupling the vacuum in said evacuated container to the interior of said reservoir, thereby drawing body fluid through the first port of said reservoir into said reservoir.

6. The method of claim 5 wherein said evacuated container is fabricated from a frangible material, and wherein said vacuum is selectively coupled to interior of said reservoir by fracturing said evacuated container.

7. The method of claim 6 wherein said cartridge includes a resilient seal covering the first port of said reservoir, a resilient tab positioned adjacent to said evacuated container, a tapered member coupled to said tab and extending radiallybeyond a sidewall of said cartridge, and a needle adapter having a cylindrical body portion, an end wall closing one end of said cylindrical body portion, and a double-ended needle projecting in opposite directions from said end wall along the axis of said body portion, the inside diameter of said body portion being just slightly larger than the outside diameter of said cartridge, and wherein said evacuated container is fractured by inserting said cartridge into said body portion until one end of said needle punctures the seal covering the first port of said reservoir and the cylindrical body portion inwardly displaces said tapered member thereby causing said tab to fracture saidevacuated container.

8. The method of claim 2 wherein said body fluid reservoir is formed by an evacuated tube having an opening covered by a resilient septum, and wherein said body fluid is drawn into said evacuated tube by inserting a needle through said resilient septum into said evacuated tube so that the vacuum in said tube draws said body fluid into said tube.

9. The method of claim 8 wherein said evacuated tube further includes a breakaway piston slidably disposed therein, and wherein said body fluid is expelled from said tube by inserting an actuating member into said breakaway piston and forcing said actuating member against said piston thereby sliding said piston in said tube to expel said body fluid through an outlet port communicating with said body fluid analyzer.

10. The method of claim 9 wherein said actuating member is a hypodermic needle having a port opening into said waste collection chamber, and wherein, after said body fluid has been analyzed, said body fluid and said analyzing fluids are conveyed to said waste collection chamber by forcing said hypodermic needle through said breakaway piston, thereby allowing fluid communication between saidwaste collection chamber and said outlet port, and then conveying said body fluid and analyzing fluid from said body fluid analyzer to said outlet port.

11. The method of claim 2 wherein a passage extends from said reservoir to said waste chamber, wherein a piston is placed in a first position to block said passage when said body fluid sample is taken from said patient, wherein said piston is placed in a second position to open said passage after the body fluid in said reservoir has been conveyed to said body fluid analyzer, and wherein said body fluid and analyzing fluids are conveyed from said body fluid analyzer to said waste collection chamber through said reservoir.

12. The method of claim 2 wherein said cartridge includes a housing having a front portion containing said reservoir and a rear portion containing a plurality of said analyzing fluids, said front and rear portions being rotatably disposed with respect to each other, one of said portions having a cartridge outlet port adapted to communicate with said body fluid analyzer, and valve means includes a first opening in the rear face of said front portion radially spaced from the central axis of said cartridge, said first opening communicating with said outlet port, said valve means furtherincluding a plurality of second openings in the front face of said rear portion, said second openings being radially spaced from the central axis of said cartridge by the same distance that said first opening is spaced from the central axis of said cartridge and being circumferentially spaced apart from each other, each of said second openings communicating with the fluid port of a respective ampule containing a respectiveanalyzing fluid, and wherein said analyzing fluids are successively conveyed from said body fluid collection cartridge to said outlet port by successively rotating said front portion with respect to said rear portion to a plurality of discrete angular orientations, thereby successively aligning said first opening with respective second openings to allow respective ampules to communicate with said outlet port.

13. The method of claim 2 wherein said step of drawing said body fluid into said body fluid reservoir is accomplished by venting said body fluid reservoir through an air-permeable, liquid-impermeable material so that body fluid can flow into said body fluid reservoir until said body fluid reservoir has been filled with said body fluid.

14. The method of claim 13 wherein said step of drawing said body fluid into said body fluid reservoir further includes selectively applying a vacuum to said body fluid reservoir through said air-permeable, liquid-impermeable material so that said vacuum draws said body fluid into said body fluid reservoir until said body fluid reservoir has been filled with said body fluid.

15. The method of claim 2 wherein said step of conveying said body fluid from said body fluid analyzer to said waste collection chamber is accomplished by forcing said body fluid from said body fluid analyzer back into said sampling cartridge.

16. The method of claim 15 wherein said body fluid analyzer has two interconnected fluid ports, wherein said body fluid reservoir communicates with one of said ports, wherein said analyzing fluid communicates with the other of said ports, and wherein said step of forcing said body fluid from said body fluid analyzer back into said sampling cartridge is accomplished by expelling said analyzing fluid into the second port of said body fluid analyzer so that said analyzing fluid displaces said body fluid back into said cartridge through said first port.

17. The method of claim 1 wherein said sampling cartridge contains a plurality of analyzing fluids are contained in respective ampules each containing a piston member, said ampules being circumferentially spaced about the central axis of said cartridge, and wherein said analyzing fluids are successively expelled from said ampules by rotating said cartridge to successively align each of said ampules with an actuating rod, and by then forcing said actuating rod into the aligned ampule to displace said piston member and expel said analyzing fluid from said ampule.

18. The method of claim 17 wherein said ampules are fabricated with a frangible wall, and wherein said actuating rod is forced through said frangible wall to make contact with said piston member.

19. The method of claim 18 wherein said actuating rod includes a hollow shaft surrounded by a concentric cylinder, and wherein said analyzing fluids are expelled from said ampules by forcing said hollow shaft through said piston member into said analyzing fluid and then forcing said concentric cylinder against said piston member to slide said piston member along said ampule, thereby forcing said analyzing fluid out of said ampule through said hollow shaft.

20. The method of claim 1 wherein said sampling cartridge contains a plurality of said analyzing fluids, and wherein said analyzing fluids are successively expelled from said sampling cartridge before or after delivering said body fluid to said body fluid analyzer.

21. The method of claim 1 wherein said analyzing fluid is stored in a chamber other than said waste collection chamber.

22. A body fluid analyzing system including a disposable sampling cartridge for use with a body fluid analyzer, said system comprising:
a waste collection chamber in said disposable sampling cartridge, said waste collection chamber being adapted to receive waste fluids from said body fluid analyzer;
an analyzing fluid contained in said sampling cartridge, said analyzing fluid being adapted for use by said body fluid analyzer;
first means for allowing said body fluid analyzer to receive said body fluid;
second means for expelling said analyzing fluid from said sampling cartridge into said body fluid analyzer; and third means for conveying said body fluid and said analyzing fluid from said body fluid analyzer into said waste collection chamber after said body fluid has been analyzed by said body fluid analyzer and said analyzing fluid has been used by said body fluid analyzer.

23. The body fluid analyzing system of claim 22 wherein said first means includes a body fluid reservoir having a first port adapted to receive a body fluid from a patient, and means for expelling said body fluid from said body fluid reservoir into said body fluid analyzer.

24. The body fluid analyzing system of claim 23 wherein said body fluid reservoir is vented through a second port which is blocked by an air-permeable, liquid-impermeable material so that body fluid flowing into said body fluid reservoir can displace air in said chamber through said material until said body fluid reservoir has been filled with said body fluid.

25. The body fluid analyzing system of claim 24 further including a vacuum source communicating with said body fluid body fluid reservoir through said air-permeable, liquid-impermeable material so that said vacuum draws said body fluid into said body fluid body fluid reservoir until said body fluid body fluid reservoir has been filled with said body fluid.

26. The body fluid analyzing system of claim 24 wherein first and second passages extend between the second port of said body fluid reservoir and said waste chamber, and wherein said air-permeable, liquid-impermeable material is disposed in said first passage, said cartridge further including a piston selectively movable between first and second positions, said piston blocking said second passage in said first position, thereby allowing said body fluid reservoir to vent into said waste chamber while preventing body fluid in said body fluid reservoir from flowing into said waste chamber, and said piston opening said second passage in said second position, thereby allowing fluid in said body fluid reservoir to flow into said waste chamber.

27. The body fluid analyzing system of claim 26 wherein said piston is movable into said body fluid reservoir toward the first port of said body fluid reservoir, thereby forcing body fluid out of said body fluid reservoir through said first port when body fluid is to be analyzed.

28. The body fluid analyzing system of claim 27 wherein the first port of said body fluid reservoir is accessible at one end of said cartridge, and wherein an aperture is formed in said cartridge at the other end of said cartridge in alignment with said piston so that said piston may be externally actuated through said aperture.

29. The body fluid analyzing system of claim 28 further including a releasable clamp formed at the end of said piston closest to said aperture whereby said piston may be externally actuated to draw said piston out of said body fluid reservoir, thereby suctioning fluid through said first port into said body fluid reservoir.

30. The body fluid analyzing system of claim 23 further including a piston that is movable into said body fluid reservoir toward the first port of said body fluid reservoir, thereby forcing body fluid out of said body fluid reservoir through said first port when said body fluid is to be analyzed.

31. The body fluid analyzing system of claim 30 wherein the first port of said body fluid reservoir is accessible at one end of said cartridge, and wherein an aperture is formed in said cartridge at the other end of said cartridge in alignment with said piston so that said piston may be externally actuated through said aperture.

32. The body fluid analyzing system of claim 31 wherein said analyzing fluid is stored in a vessel that is accessible at the end of said cartridge containing said aperture.

33. The body fluid analyzing system of claim 32 wherein at least a portion of the wall of said vessel facing said the end of said cartridge containing said aperture is formed of a frangible material so that the analyzing fluid in said vessel may be accessed by puncturing said vessel from the same end of said cartridge through which said piston is actuated.

34. The body fluid analyzing system of claim 31 wherein said piston extends along the longitudinal axis of said cartridge, wherein said sampling cartridge contains a plurality of vessels each storing a respective analyzing fluid, and wherein said vessels are circumferentially spaced around said piston.

35. The body fluid analyzing system of claim 23 further including an evacuated container positioned within said cartridge, said cartridge further including means of selectively coupling the vacuum in said evacuated container to the interior of said body fluid reservoir, thereby drawing body fluid through the first port of said body fluid reservoir into said body fluid reservoir whereby said cartridge may be used for collecting venous body fluid.

36. The body fluid analyzing system of claim 35 wherein said evacuated container is fabricated from a frangible material, and wherein said means for selectively coupling the vacuum in said evacuated container to the interior of said body fluid reservoir includes fracturing means for breaking said evacuated container.

37. The body fluid analyzing system of claim 36 wherein said fracturing means includes a resilient tab positioned adjacent to said evacuated container, said tab being externally accessible so that it may be forced through a wall of said evacuated container to couple the vacuum in said evacuated container to said body fluid reservoir.

38. The body fluid analyzing system of claim 37 further including a resilient seal covering the first port of said body fluid reservoir, and a tapered member coupled to said tab and extending radially beyond a sidewall of said cartridge, and wherein said cartridge further includes a needle adapter having a cylindrical body portion, an end wall closing one end of said cylindrical body portion, and a double-ended needle projecting in opposite directions from said end wall along the axis of said body portion, the inside diameter of said body portion being just slightly larger than the outside diameter of said cartridge so that inserting said cartridge into said body portion causes one end of said needle to puncture the seal covering the first port of said body fluid reservoir and the cylindrical body portion to inwardly displace said tapered member, thereby causing said tab to fracture said evacuated container.

39. The body fluid analyzing system of claim 23 wherein said body fluid reservoir is formed by an evacuated tube having an opening covered by a resilient septum so that said body fluid may be drawn into said evacuated tube by inserting a needle communicating with said body fluid through said resilient septum and into said evacuated tube.

40. The body fluid analyzing system of claim 39 wherein said first means for expelling said body fluid includes a breakaway piston slidably disposed in said evacuated tube, and an actuating member adapted to force said breakaway piston against said piston, thereby sliding said piston in said tube to expel said body fluid through an outlet port communicating with said body fluid analyzer.

41. The body fluid analyzing system of claim 40 wherein said actuating member includes a hypodermic needle having a port opening into said waste collection chamber so that, after said body fluid has been analyzed, said body fluid and said analyzing fluids may be conveyed to said waste collection chamber by forcing said hypodermic needle through said breakaway piston, thereby allowing fluid communication between said waste collection chamber and said outlet port.

42. The disposable sampling of cartridge of claim 23 wherein said cartridge includes a housing having a front portion and a rear portion rotatablydisposed with respect to each other, one of said portions having a cartridge outlet port adapted to communicate with said body fluid analyzer, said front portion containing said body fluid reservoir, and said rear portion including connecting means for connecting said body fluid reservoir and said outlet port when said front portion is rotated with respect to said rear portion to a first predetermined angular orientation.

43. The body fluid analyzing system of claim 42 wherein said front portion further includes a vent line for venting air from said body fluid reservoir when body fluid flows into said body fluid reservoir through said first port, and wherein said connecting means connects said body fluid reservoir to said vent line when said front portion is rotated with respect to said rear portion to a second predetermined angular orientation.

44. The body fluid analyzing system of claim 42 wherein said waste collection chamber is disposed in said front portion, and wherein said front portion includes a cartridge inlet port communicating with said waste collection chamber for receiving said waste fluids from said body fluid analyzer.

45. The body fluid analyzing system of claim 42 wherein said first means for expelling said body fluid from said body fluid reservoir includes a piston slidably disposed in said body fluid reservoir for pumping said body fluid therefrom.

46. The body fluid analyzing system of claim 42 wherein said analyzing fluid is stored in a vessel, and wherein said second means for expelling said analyzing fluid from said vessel includes an externally actuatable piston disposed in said vessel.

47. The body fluid analyzing system of claim 46 wherein said actuatable piston includes a piston member slidably disposed in said vessel, and a frangible wall in the rear face of said vessel for allowing said piston member to be actuated through the rear face of said vessel.

48. The body fluid analyzing system of claim 46 wherein said vessel includes a fluid port, and wherein said cartridge includes valve means for coupling said fluid port to said outlet port depending on the angular position of said rear portion with respect to said front portion.

49. The body fluid analyzing system of claim 46 wherein said sampling cartridge contains a plurality of analyzing fluids in respective cartridges, and wherein said valve means includes a first opening in the rear face of said front portion radially spaced from the central axis of said cartridge, said first opening communicating with said outlet port, said valve means further including a plurality of second openings in the front face of said rear portion, said second openings being radially spaced from the central axis of said cartridge by the same distance that said first opening is spaced from the central axis of said cartridge and being circumferentially spaced apart from each other, each of said second openings communicating with the fluid port of a respective vessel so that rotation of said front portion with respect to said rear portion to a plurality of discrete angular orientations aligns said first opening with respective second openings, thereby allowing respective vessels to communicate with said outlet port.

50. The body fluid analyzing system of claim 23 further including means for forcing said body fluid from said body fluid analyzer back into said sampling cartridge after said body fluid has been analyzed, thereby conveying said body fluid from said body fluid analyzer to said waste collection chamber.

51. The body fluid analyzing system of claim 50 wherein said body fluid analyzer has two interconnected fluid ports, wherein said body fluid body fluid reservoir communicates with one of said ports, wherein said analyzing fluid communicates with the other of said ports, and wherein said means for forcing said body fluid from said body fluid analyzer back into said sampling cartridge comprises said second means for expelling said analyzing fluid into said body fluid analyzer so that said analyzing fluid flows into the second port of said body fluid analyzer and displaces said body fluid back into said cartridge through said first port.

52. The body fluid analyzing system of claim 22 wherein said analyzing fluid is stored in a chamber other than said waste collection chamber.

53. The body fluid analyzing system of claim 22 wherein said sampling cartridge contains a plurality of analyzing fluids stored in respective vessels, and wherein said second means successively expels said analyzing fluids from said sampling cartridge before or after said first means delivers said body fluid to said body fluid analyzer.

C:\APPLICAT\8738529-12/16/92